package Main;
/*
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* and open the template in the editor.
*/
import java.io.*;
import java.security.*;
import java.util.*;
/**
*
* @author phihai
*/
public class Chunks {
public static long chunkSize = 512* 1024;
public void split(File f) throws FileNotFoundException, IOException // Cắt chunks
{
BufferedInputStream in = new BufferedInputStream(new FileInputStream(f));
long fileSize = f.length();
int subfile;
for (subfile = 0; subfile < fileSize / chunkSize; subfile++)
{
BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream("Share\\"+f.getName() + "." + subfile));
for (int currentByte = 0; currentByte < chunkSize; currentByte++)
{
out.write(in.read());
}
out.close();
}
if (fileSize != chunkSize * (subfile - 1))
{
BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream("Share\\"+f.getName() + "." + subfile));
int b;
while ((b = in.read()) != -1)
out.write(b);
out.close();
}
in.close();
Info_Chunk("Share\\"+f.getName());
}
public void join(String baseFilename) throws IOException // ghép chunks , basefilename là đường dẫn của tập tin
{
int numberParts = getNumberParts(baseFilename);
BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(baseFilename));
for (int part = 0; part < numberParts; part++)
{
BufferedInputStream in = new BufferedInputStream(new FileInputStream(baseFilename + "." + part));
int b;
while ( (b = in.read()) != -1 )
out.write(b);
in.close();
}
out.close();
}
private static int getNumberParts(String baseFilename) throws IOException // đến số lượng chunks
{
File directory = new File(baseFilename).getAbsoluteFile().getParentFile();
final String justFilename = new File(baseFilename).getName();
String[] matchingFiles = directory.list(new FilenameFilter()
{
public boolean accept(File dir, String name)
{
return name.startsWith(justFilename) && name.substring(justFilename.length()).matches("^\\.\\d+$");
}
});
return matchingFiles.length;
}
public String[] getFileName(String dirname) throws IOException // lấy tên các tập tin có thể download từ file (filename.chunk)
{
File directory = new File(dirname);
String[] matchingFiles = directory.list(new FilenameFilter()
{
public boolean accept(File dir, String name)
{
return name.endsWith(".chunk");
}
});
return matchingFiles;
}
public void Info_Chunk(String baseFilename) throws IOException // xuất thông tin file + mã hash của tập tin vào file filenamme.chunks
{
String str;
int numberParts = getNumberParts(baseFilename);
File file = new File(baseFilename + "."+"chunk");
BufferedWriter out = new BufferedWriter(new FileWriter(file));
for (int part = 0; part < numberParts; part++)
{
str = part + " " + hash(baseFilename + "." + part) + "\r\n";
out.write(str);
}
out.close();
System.out.print(file.getName() +" đã được tạo \n");
}
// public String List_Chunk(String baseFilename) throws IOException
// {
// File directory = new File(baseFilename).getAbsoluteFile().getParentFile();
// final String justFilename = new File(baseFilename).getName();
// String[] matchingFiles = directory.list(new FilenameFilter()
// {
// public boolean accept(File dir, String name)
// {
// return name.startsWith(justFilename) && name.substring(justFilename.length()).matches("^\\.\\d+$");
// }
// });
//
// List<String> list = getHash(justFilename+".chunk");
// String str = "";
//
// for (int part = 0; part < matchingFiles.length; part++)
// {
// if(list.contains(hash(matchingFiles[part])))
// {
// str += matchingFiles[part] + "\r\n";
// }
// }
// return str;
// }
public List<String> List_Chunk(String baseFilename) throws IOException // Lay danh sach Hash cua cac file hien co trên client thực thi
{
File directory = new File(baseFilename).getAbsoluteFile().getParentFile();
final String justFilename = new File(baseFilename).getName();
String[] matchingFiles = directory.list(new FilenameFilter()
{
public boolean accept(File dir, String name)
{
return name.startsWith(justFilename) && name.substring(justFilename.length()).matches("^\\.\\d+$");
}
});
List<String> list = new ArrayList<String>();
for (int part = 0; part < matchingFiles.length; part++)
{
list.add(hash("Share\\"+matchingFiles[part]));
}
return list;
}
public String Check_Chunks(String hashChunks) // nhận thông tin mã hash từ client thực thi, client nhận hash sẽ tiến hành kiểm tra tồn tại của file thông qua mã hash này
{
String temp = "";
File folder = new File("Share\\");
File[] listOfFiles = folder.listFiles();
for(int i=0;i<listOfFiles.length;i++)
{
if(listOfFiles[i].isFile())
{
if(hash(listOfFiles[i].getAbsolutePath()).equals(hashChunks))
{
temp = listOfFiles[i].getName();
break;
}
}
}
return temp;
}
// public List<String> Find_Chunks(String baseFilename) // Tim cac chunks chua co
// {
// List<String> listFile = new ArrayList<String>();
// final String justFilename = new File(baseFilename).getName();
// try
// {
// String str ;
// List<String> list = List_Chunk(baseFilename);
//
// BufferedReader br = new BufferedReader(new FileReader(justFilename+".chunk"));
// System.out.print("Cac Chunk còn thiếu:\n");
// while ((str = br.readLine()) != null)
// {
// String []array = str.split(" ");
// if(!list.contains(array[1]))
// {
// listFile.add(array[1]);
// System.out.print(array[0]+"\n");
// }
// }
// }
// catch (Exception e)
// {
// e.printStackTrace();
// }
// return listFile;
// }
// private static List<String> getHash(String Filename)
// {
// List<String> list = new ArrayList<String>();
// try
// {
// String str ;
//
// BufferedReader br = new BufferedReader(new FileReader(Filename));
// while ((str = br.readLine()) != null)
// {
// String []array = str.split(" ");
// list.add(array[1]);
// }
// }
// catch (Exception e)
// {
// e.printStackTrace();
// }
// return list;
// }
public static String hash(String filename) // filename đường dẫn của file, lấy thông tin của file hash ra mã SHA-1
{
String result = "";
try
{
BufferedInputStream in = new BufferedInputStream(new FileInputStream(filename));
MessageDigest md = MessageDigest.getInstance("SHA-1");
byte [] buffer = new byte[1024];
int sizeRead;
while ((sizeRead = in.read(buffer)) != -1)
{
md.update(buffer, 0, sizeRead);
}
in.close();
byte [] hash = md.digest();
for (int i=0; i < hash.length; i++) {
result += Integer.toString( ( hash[i] & 0xff ) + 0x100, 16).substring( 1 );
}
}
catch (Exception ex)
{
ex.printStackTrace();
}
return result;
}
}
